Storing a GKE key in our travis build

Hello all,
I wanted to ask about us moving away from minikube for our airflow
kubernetes builds.
1. It takes a long time to build
Building minikube from scratch every time takes the lionshare of our travis
testing time. If we can just connect to GKE and launch a cluster in a few
seconds, we'll get much faster feedback for whether our changes are working
or not.
2. It doesn't really mimic real world kubernetes
We've run into a few bugs in the wild where our minikube-based testing
worked fine but we found issues when performing on a multi-node cluster.
Many in the k8s community are even moving away from minikube because of
these differences in behavior.
3. It makes local testing a pain
Over the next few months I want to start figuring out ways to make
iterative local testing of airflow easier. An ideal for k8s-based testing
to launch a GKE cluster and just run a script every time we want to test
our changes. This would simplify onboarding new devs and reduce the time to
approve PRs.
*Proposal: Create GKE testing that committers can turn on*
When users submit PRs to kubernetes, there seems to be a buildbot setting
that allows the committers to turn on integration testing on the
CloudNative clusters. I'm thinking if all k8s testing is reformatted to
assume kubernetes rather than minikube, then users can test as much as they
want on their own local/GKE clusters and then we can turn on GKE before
merging.
Google had spoken with us a while back about giving a GKE account for
airflow integration, and I wanted to open this up to the community if
anyone had strong feelings either way.